Microplastic concentrations in surface water and sediment of Thuan An and Tra Khuc estuaries in Central Vietnam, 2021

Microplastic concentrations (300-5000µm) in surface water and sediment were investigated in two estuaries in Central Vietnam: Thuan An Estuary (Thua Thien Hue Province) and Tra Khuc Estuary (Quang Ngai Province) in April 2021. Microplastics in water were sampled using a stainless steel bucket and filtered through a plankton net (mesh size: 80 μm). Sediment sampling was implemented using a stainless steel sediment core sampler (diameter: 5 cm). Microplastics in the samples were treated by bio-enzyme and H2O2 30%, density separated by NaCl, and filtered through Whatman glass fiber filters (GF/A, pore sizes of 1.6 μm). Microplastics were observed by a stereomicroscope and classified into groups of shape, color, and size. Microplastic concentration was expressed as the number of particles per m3 (item m-3) for water and the number of particles per kilogram of dry-weight sediment (item kg-1) for sediments.